1. Field of the Invention
The present invention relates to an image pickup device and more particularly to a drive apparatus for the image pickup device.
2. Related Background Art
When a solid state image pickup element, for example, a CCD, is used in a television camera, the use of so-called double-correlation sampling of the output circuit of the camera can reduce the reset noise to improve the S/N ratio. In this instance, in the double-correlation sampling circuit, the three (clamp, sample and hold, and reset) pulses are required to have predetermined phase differences among them.
In such a case, if the clamp, sample and hold (hereinafter referred to as the S/H), and reset pulses are used, each being 120 degrees out of phase with the others and each having a duty cycle of 1/3, one pulse will rise while one of the other two pulses is falling. Thus, noise is likely to be mixed into the desired signal during clamping or sampling and holding and a fixed pattern noise, etc., will increase.